Abstract: Objective To study the expression of basic fibroblast grouth factor (bFGF) and transforming growth factor β1 (TGF-β1) in different stages of myocardial fibrosis (CFs). Methods CFs of neonatal Sprague-Dawley rats were isolated with the method of trypsin digestion and differential anchoring velocity, then cultured in vitro. The generation 2-4 of CFs were used for the experiment and randomly divided into 2 groups: the control group were cultured without AngII , and the test group were cultured with AngII 10-6 mol/L. The test group were cultured for 12, 24, 48, and 72 h respectively, and then the synthesis of collagen were measured by ELISA, the bFGF, TGF-β1-mRNA expression was measured by RT-PCR, and the bFGF and TGF-β1 protein expression was measured by western blot analyses. Results Compared with those of control group, the expressions of bFGF and TGF-β1 both in gene and in protein in the test groups increased gradually with the timing (P < 0.01). Correlation analysis found that the expression of bFGF mRNA and protein were positively associated with TGF-β1 mRNA and protein (r = 0.967, 0.947, P < 0.05), and both bFGF and TGF-β1 were positively associated with the supernatant collagen. (r = 0.932, 0.881, 0.930, 0.896, P< 0 .05). Conclusion bFGF and TGF-β1 may be involved in the occurrence and development of myocardial fibrosis.